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CT colonography (CTC) is growing in its utilization and availability as a screening or diagnostic test for colorectal cancer detection. Its performance stands up to optical colonoscopy and it has become a growing alternative in many situations. This leaves a rising need for training and proficiency in how to perform and interpret CTC. Optimization of exam technique and colonic preparation raises the detection rate of colorectal lesions and renders interpretation easier. Since colorectal cancer remains the second most common cause of cancer death in the United States in men and women combined, the role for CTC is further fortified.

CT colonography (CTC), also known as “virtual colonoscopy,” is a minimally invasive complementary screening method to optical colonoscopy (OC) that is growing in its availability and utilization. As a screening test, it is typically performed in outpatient radiology sites. Examinations are monitored by a radiologist trained in its performance. CTC is selectively performed in a hospital setting for patients with comorbidities that render them at a high risk for OC, such as cardiac disease or screening before organ transplantation. In cases where OC is unsuccessful for at complete colonic inspection, CTC can be performed the same day after OC or planned at a later date to evaluate the remainder of the colon. Candidates for CTC must be able to follow instructions and tolerate colonic insufflation. Patients who have fecal incontinence or significant rectal prolapse are not candidates for CTC because of limited ability to maintain colonic distension. Finally, strict adherence to the recommended colonic preparation before CTC is critical to the examination's success.

The coronavirus disease 2019 (COVID-19) pandemic caused by the novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) has affected almost every country in the world resulting in severe morbidity, mortality and economic hardship, altering the landscape of healthcare forever. Its devastating and most frequent thoracic and cardiac manifestations have been well reported since the start of the pandemic. Its extra-thoracic manifestations are myriad and understanding them is critical in diagnosis and disease management. The role of radiology is growing in the second wave and second year of the pandemic as the multiorgan manifestations of COVID-19 continue to unfold. Musculoskeletal, neurologic and vascular disease processes account for a significant number of COVID-19 complications and understanding their frequency, clinical sequelae and imaging manifestations is vital in guiding management and improving overall survival. The authors aim to provide a comprehensive overview of the pathophysiology of the virus along with a detailed and systematic imaging review of the extra-thoracic manifestation of COVID-19. In Part I, abdominal manifestations of COVID-19 in adults and multisystem inflammatory syndrome in children will be reviewed. In Part II, manifestations of COVID-19 in the musculoskeletal, central nervous and vascular systems will be reviewed.

Colostomies are commonly created in conjunction with colorectal surgery performed for both malignant and benign indications. Familiarity with the different types of colostomies and their normal imaging appearance will improve radiologic detection and characterization of colostomy complications. The radiologist plays a large role in assessment of colostomy patients either via fluoroscopic technique or multidetector computed tomography (CT) in order to help identify ostomy complications or to aid the surgeon prior to colostomy reversal. In this article, we will review: (1) the types of colostomies and indications for their creation; (2) the proper radiographic technique of ostomy evaluation; and (3) the potential complications of colostomies and their imaging manifestations.

Ultrasound is the primary imaging modality used in the evaluation of first-trimester vaginal bleeding and pelvic pain. This article will summarize the ultrasound findings in normal first-trimester pregnancy, failed pregnancy, ectopic pregnancy, subchorionic hemorrhage, retained products of conception, and gestational trophoblastic disease. Mastery of the spectrum of sonographic findings in the normal and abnormal first-trimester pregnancy allows the radiologist to make accurate diagnoses and helps to appropriately guide patient management.

The purpose of this article is to determine the natural history of adrenal cysts on the basis of long-term imaging follow-up.This retrospective study included patients with adrenal cysts who had at least 12 months of imaging follow-up (1993-2010). Medical records were reviewed. Two radiologists reviewed imaging examinations in consensus and recorded wall thickness (thin, ≤ 3 mm; thick,3 mm), septations, and calcification. CT attenuation value, MRI signal intensity, the presence or absence of enhancement, and typical sonographic features were used to confirm fluid content of the lesions. Cyst wall enhancement was recorded (thin, ≤ 3 mm and smooth; thick,3 mm). Cyst diameter on the initial and most remote follow-up examinations was compared. The Wilcoxon matched-pairs signed rank test was applied to assess statistically significant differences in size and CT attenuation on follow-up examinations.Twenty patients with unilateral adrenal cysts (seven male and 13 female patients; mean age, 44 years; range, 10-75 years) had a mean imaging follow-up period of 64 months (range, 12-198 months). CT, MRI, and ultrasound examinations were obtained in 19, 11, and 13 patients, respectively. Cysts were diagnosed by lack of enhancement on CT or MRI in 12 patients, typical sonographic features in three patients, and combination of CT and sonographic or MRI features in five patients. Signal intensities typical for fluid were found on all MRI examinations, attenuations of less than 20 HU on 17 of 19 (89%) CT examinations, and features of either simple or mildly complicated cysts on all sonograms. Thin walls, wall calcifications, and thin septations were found in 20 (100%), 12 (60%), and four (20%) lesions, respectively. During the follow-up of 20 lesions, the median cyst diameter increased by 26.0% (interquartile range, 6.8-68.4%) in 12 (60%) patients, decreased by 32.9% (interquartile range, 7.1-42.8%) in six (30%) patients, and was unchanged in two (10%) patients. The median baseline CT attenuation values did not significantly change on follow-up CT examinations (p = 0.72). No patient developed a complication of adrenal cyst. Four patients had histologically confirmed benign adrenal cysts.Interval enlargement of an adrenal cyst is frequent and as an isolated finding does not indicate malignancy or presence of a complication. However, some adrenal cysts may decrease or remain stable in size over time.

Purpose: To identify factors influencing hepatobiliary phase (HBP) hepatic enhancement on gadoxetate disodium-enhanced MRI in patients with chronic liver disease (CLD). Materials and Methods: We retrospectively reviewed abdominal gadoxetate disodium-enhanced MRIs and medical records of patients with (n = 97) and without (n = 48) CLD. CLD subgroups were formed based on normal/abnormal components of liver function tests (LFTs). Hepatic enhancement coefficients (HEKs) were calculated on MRI, and compared with LFTs and Model for End-stage Liver Disease (MELD) scores. Results: The mean HEK was significantly lower (P < 0.0008) in the CLD than control group. The mean HEK was similar to controls in the subgroup with all normal LFTs (P = 0.09) and subgroup with normal direct bilirubin (DB) (p = 0.09), while it was significantly reduced (P < 0.0001) in the subgroup with elevated DB. For all other LFT components, regardless of normal or abnormal values, there was a significant reduction in the mean HEKs versus controls (all P values

To evaluate frequency and clinical relevance of the 'small bowel faeces' sign (SBFS) on computed tomography (CT) in patients with and without small bowel obstruction (SBO) presenting with acute abdominal or acute abdominal and flank pain.Abdominal CTs of consecutive patients presenting to the emergency department with abdominal or flank pain over a 6 month period were retrospectively reviewed by six radiologists, independently, for the presence of the SBFS. Examinations with positive SBFS were further evaluated in consensus by three radiologists, blinded to the final diagnosis. The small bowel was graded as non-dilated (2.5 cm) and mildly (2.5-2.9 cm), moderately (3-4 cm) or severely (4 cm) dilated. The location of SBFS and presence of distal small bowel collapse indicative of SBO was recorded. Imaging findings were subsequently correlated with the final diagnosis via chart review and compared between patients with and without SBO.Of 1642 CT examinations, a positive SBFS was found in 100 (6%) studies. Of 100 patients with a positive SBFS, 32 (32%) had documented SBO. The remaining 68 patients had other non-obstructive diagnoses. SBFS was located in proximal, central, distal and multisegmental bowel loops in one (3.1%), eight (25.0%), 21 (65.6%) and two (6.3%) patients with SBO, and in zero (0%), 10 (14.7%), 53 (77.9%) and five (7.4%) of patients without SBO (p0.273). The small bowel was non-dilated and mildly, moderately or severely dilated in one (3%), five (16%), 20 (62%) and six (19%) patients with SBO, and in 61(90%), seven (10%), zero (0%) and zero (0%) patients without SBO. Normal or mildly dilated small bowel was seen in all (100%) patients without SBO, but only in six (19%) of 32 patients with SBO (p0.0001). Moderate or severe small bowel dilatation was seen in 26 (81%) patients with SBO (p0.0001), but it was absent in patients without SBO. Distal small bowel collapse was found in 27 (84.4%) of 32 patients with SBO, but not in patients without SBO (p0.0001). A combination of SBFS, moderate or severe small bowel distension and distal collapse was found in 23 (71.9%) patients with SBO (p0.0001), but was not found in patients without SBO.A SBFS is more frequent in patients presenting with acute abdominal/flank pain without bowel obstruction. When seen in association with moderate or severe small bowel dilatation, a SBFS is significantly more common in patients with SBO. When a SBFS is associated with normal or mildly dilated small bowel, the majority of patients have no bowel obstruction.

Acute hollow organ ischemia commonly presents with acute pain prompting radiologic evaluation and almost always requires urgent treatment. Despite different risk factors and anatomic differences, ischemia is commonly due to low flow states but can also be due to arterial and venous occlusion. Radiologic diagnosis is critical as many present with nonspecific symptoms. Contrast-enhanced computed tomography (CT) is the modality of choice. Magnetic resonance imaging (MRI) is preferred in suspected appendicitis in pregnant patients and is superior in biliary necrosis. This article provides a pictorial review of the CT/MRI features of hollow abdominal organ ischemia while highlighting key clinical features, pathogenesis, and management.

ObjectivesWe noted substantial differences when measuring repeatedly the same abdominal aortic aneurysm (AAA) on the same computed tomography (CT) scan. This study quantitated this variability, and methods to minimize it were developed.MethodsThe CT maximal diameter of 25 AAAs was measured by eight experienced observers, including six vascular surgeons and two radiologists, using two methods: an unstandardized protocol, and a standardized protocol using fine calipers to carefully measure the largest diameter perpendicular to the estimated aneurysm centerline, from outer aneurysm wall to outer wall. The average measurement difference between observers was calculated for each method. The average difference between each observer's measurement and the official radiology report value was also calculated. Agreement between the two measurement methods was assessed with Bland-Altman plots.ResultsThe difference in maximal diameter measurements between each observer averaged 4.0 ± 5.1 mm (range, 0.0-35.0 mm) with the unstandardized method. The mean measurement difference with the standardized protocol was significantly lower, and averaged 2.8 ± 4.4 mm (range, 0.0-26.0 mm; P < .05). Measurements taken from the official radiology report differed from each of the observer's standardized measurement by an average of 5.0 ± 6.3 mm (range, 0.0-28.0 mm). This difference was similar for both the unstandardized and standardized methods. Bland-Altman plots confirmed the wide variation of the maximal diameter measurements when the unstandardized method was compared with the standardized method (95% confidence interval, −9-9 mm).ConclusionsRoutine CT maximal diameter measurement of AAAs can have substantial interobserver variability. Standardized measurement protocols can decrease, but not eliminate, this measurement variability. Thus apparent size changes based on CT measurements may represent measurement artifact rather than actual aneurysm growth or shrinkage, particularly when a standardized system is not used.

Objective. Pregnant patients without a sonographically visible intrauterine pregnancy and with a thick-walled cystic adnexal structure present a dilemma. This study compared the utility of various sonographic features in differentiating between the tubal ring of ectopic pregnancy and the corpus luteum. Methods. Retrospective review of first-trimester transvaginal sonograms revealed a cystic adnexal structure in 79 women. Each structure was evaluated for 6 specific sonographic characteristics: echogenicity of its wall compared with that of the ovary and endometrium, wall thickness in 2 planes, color Doppler flow distribution and percentage of wall circumference, and internal texture. Results. Forty-one (52%) of the 79 women had ectopic pregnancies, and 38 (48%) had corpora lutea. Eleven (32%) of 35 ectopic walls were more echogenic than the endometrium, compared with none of the corpora lutea. A cyst wall less echogenic than the endometrium was more likely in corpora lutea (84% versus 31%; P < .0001). More than twice as many ectopic rinds were more echogenic than ovarian tissue compared with corpora lutea (76% versus 34%; P < .0001). The only predictive internal texture feature was a clear pattern, which was more common in the corpora lutea (P < .01, Fisher exact test). There was no significant difference in mural flow distribution or extent between the 2 groups. Conclusions. Ancillary sonographic signs to distinguish between an ectopic pregnancy and a corpus luteum include decreased wall echogenicity compared with the endometrium and an anechoic tex

To assess unenhanced and delayed phase computed tomographic (CT) images combined with arterial phase images for detecting endoleaks after endovascular treatment for abdominal aortic aneurysm (AAA).CT scans were retrospectively evaluated for the presence of endoleaks after endovascular treatment of AAAs in 33 patients with endoleak (positive group) and 40 patients without evidence of endoleak or aneurysm enlargement (negative group). All patients underwent unenhanced and biphasic contrast material-enhanced CT. The CT scans were reviewed in the following combinations: (a) arterial phase and unenhanced scans (uniphasic/unenhanced set), (b) arterial and delayed phase scans only (biphasic set), and (c) arterial and delayed phase scans with unenhanced scans (complete set). Each set was reviewed by two radiologists blinded to the diagnosis of endoleak. Findings were recorded as positive, negative, or indeterminate for endoleak.Within the positive group, endoleaks were diagnosed with the uniphasic/unenhanced, biphasic, and complete image sets in 30 (91%), 32 (97%), and 33 (100%) patients, respectively. With the uniphasic/unenhanced set, three (9%) endoleaks (seen only on delayed phase images) were missed. With the biphasic set, one (3%) endoleak was interpreted as indeterminate. Within the negative group, uniphasic/unenhanced, biphasic, and complete image sets were negative for endoleaks in 100%, 80%, and 100% of patients, respectively. With the biphasic set, results were indeterminate in 20% of cases.A delayed CT acquisition enables detection of additional endoleaks, while an unenhanced acquisition helps eliminate indeterminate results. Thus, both acquisitions contribute to accurate diagnosis of endoleaks when combined with an arterial phase acquisition.

The present study was designed to elucidate whether demonstration of a peripheral bronchopleural fistula on CT correlated with the need for surgical management. We retrospectively identified 33 patients, 24 males and nine females, mean age 38 years, with clinical diagnosis of peripheral bronchopleural fistula and whose chest CT scans and medical charts were reviewed. Each chart was reviewed to identify the cause of the peripheral bronchopleural fistula and its treatment. Treatment decisions were categorized as surgical or conservative. Each chest CT was evaluated for the cause of peripheral bronchopleural fistula as follows: bulla(e), lung abscess/necrotizing pneumonia, neoplasms, peripheral bronchiectasis, and trauma. The peripheral bronchopleural fistula was classified as visible on CT if a distinct channel between the lung or a peripheral bronchus and the pleura was seen on the lung windows. We found that CT was useful in guiding surgery by identifying and localizing the cause of the peripheral bronchopleural fistula in the 55% (18/33) of patients who required surgery. The peripheral bronchopleural fistula or its probable cause was identified in 91% (30/33) as follows: bulla(e) (n = 12), lung abscess/necrotizing pneumonia (n = 11), peripheral bronchiectasis (n = 5), malignancy (n = 1), and posttraumatic pneumatocele (n = 1). The peripheral bronchopleural fistula was right-sided in 24, left-sided in nine, and was visible on CT in 36% (12/33). Among the patients with bullae, 58% (7/12) required surgery; however, the peripheral bronchopleural fistula was visible on CT in only 8% (1/12). Among the 21 patients without bulla(e), the peripheral bronchopleural fistula was visible on CT in 52% (11/21). When the fistula was visible in this subgroup, 73% (8/11) required surgery compared with 30% (3/10) in whom the fistula was not visible (p = NS; Fisher exact). In conclusion, CT was useful in guiding surgery by identifying and localizing the peripheral bronchopleural fistula or its probable cause. Peripheral bronchopleural fistulas caused by bulla(e) were less likely to be visible on CT (p < 0.05). Excluding patients with bulla(e), our data suggest a trend toward the need for surgical management for patients in whom the peripheral bronchopleural fistula was visible on CT.

Incompetent and dilated ovarian veins have been reported in association with pelvic congestion syndrome. We postulate that incompetent and dilated ovarian veins are often an incidental CT finding, with a low diagnostic value. To verify our hypothesis, we studied the frequency of incompetent and dilated ovarian veins seen on CT in asymptomatic women.We retrospectively analyzed helical CT scans and medical records of 34 consecutive female renal donors between 18 and 46 years old (mean age, 33 years). An incompetent and dilated ovarian vein was defined as a contrast-filled vein measuring 7 mm or greater, seen during the arterial phase of helical CT.Incompetent and dilated ovarian veins were found in 16 (47%) of 34 asymptomatic women. All 16 women had left ovarian vein involvement; six (37.5%) had bilateral involvement. The mean diameters for the left and right (incompetent and dilated) ovarian veins were 9.1 mm and 8.8 mm, respectively (range, 7-12 mm). Of 16 women with incompetent and dilated ovarian veins, 15 (94%) were parous. Of 18 women with normal ovarian veins, nine (50%) were parous. Overall, incompetent and dilated ovarian veins were found in 15 (63%) of 24 parous women, and in one (10%) of 10 nonparous women (p0.05).Incompetent and dilated ovarian veins are frequently seen on CT in asymptomatic parous women. As an isolated finding, it is unlikely to be associated with pelvic congestion syndrome.

Purpose of Study: To investigate frequency and morphology of focal pelvic lesions (FPLs) in patients after open inguinal hemioplasty with a prosthetic mesh. Materials, Methods and Procedures: Patients who had open prosthetic inguinal hernioplasties between 1999 and 2004 and subsequent pelvic computed tomography were identified. Computed tomography of each patient was evaluated by 2 observers. The presence of an FPL at the internal inguinal ring (IIR) and its shape, size, and attenuation were recorded. The findings were compared with the type of surgical mesh used for the repair. Results: There were 93 patients, 86 men, with a mean age of 62.4 years (range, 14-89 years) who underwent 96 hernioplasties, with plug or flat mesh used in 71 and 25 cases, respectively. There were 96 computed tomographies obtained between 1 and 46 months (mean, 15.4 months) after surgery. Focal pelvic lesions were identified in 69 (72%) of 96 cases. Focal pelvic lesions were found in 63 (89%) of 71 cases repaired with a plug, but in only 6 (24%) of 25 cases repaired with a flat mesh (P

To retrospectively assess endoleak shapes and locations within aneurysms to differentiate type II from type I and type III endoleaks.The institutional review board granted an exemption for this HIPAA-compliant study; patient informed consent was not required. A retrospective review of arterial phase helical computed tomographic (CT) studies and medical records was performed for 39 patients (29 men, 10 women; age range, 60-89 years; mean, 78.5 years) who had an endoleak after endoaortic graft implantation for treatment of abdominal aortic aneurysm and who subsequently underwent angiography (n = 25), surgery (n = 8), or long-term follow-up (n = 6) to classify their endoleak into a specific type. At CT, endoleak shape (tubular or nontubular) and location (central or peripheral) were recorded. An endoleak was classified as type II if it contained a peripheral tubular component (PTC) near the aortic wall, with or without an identifiable feeding vessel. Endoleaks without these features were classified as type I or III. The Fisher exact test was used to assess associations between CT findings and endoleak type.There were 22 type II and 17 type I or III endoleaks. CT enabled correct identification of 22 (100%) of 22 type II endoleaks, all of which contained a PTC. Of 17 type I or III endoleaks, only two (12%) contained a PTC and were misclassified as type II endoleaks; the remaining 15 (88%) were correctly classified. Overall, CT enabled correct identification of endoleaks as type II or type I or III in 37 (95%) of 39 patients. PTCs were significantly more common (P.001) in type II than in type I or III endoleaks, with a sensitivity, specificity, accuracy, negative predictive value, and positive predictive value of 100%, 88.2%, 94.9%, 100%, and 91.7%, respectively.A PTC is a statistically significant predictor of type II endoleak in most patients.